On Wed, May 3, 2023 at 8:26 AM Dave Hansen [off-list ref] wrote:

On 5/3/23 08:18, Suren Baghdasaryan wrote:

quoted

quoted

quoted

+static inline void rem_ctx(struct codetag_ctx *ctx,
+                        void (*free_ctx)(struct kref *refcount))
+{
+     struct codetag_with_ctx *ctc = ctx->ctc;
+
+     spin_lock(&ctc->ctx_lock);

This could deadlock when allocator is called from the IRQ context.

I see. spin_lock_irqsave() then?

Yes.  But, even better, please turn on lockdep when you are testing.  It
will find these for you.  If you're on x86, we have a set of handy-dandy
debug options that you can add to an existing config with:

        make x86_debug.config

Nice!
I thought I tested with lockdep enabled but I might be wrong. The
beauty of working on multiple patchsets in parallel is that I can't
remember what I did for each one :)

That said, I'm as concerned as everyone else that this is all "new" code
and doesn't lean on existing tracing or things like PAGE_OWNER enough.

Yeah, that's being actively discussed.